Collision avoidance systems attempt to prevent collisions between a vehicle and other objects, which can be stationary and/or moving. The collision avoidance systems are sometimes used for automobiles, trucks, vehicles with trailers, planes (when traveling on the ground), heavy equipment such as fork lifts, bulldozers, scrapers and the like, boats, ships, tractor trailers and other types of vehicles. Collision avoidance systems may include one or more sensors that are positioned at various locations on the vehicle, a controller that communicates with the sensors, and a warning device such as an audio, visual and/or haptic device that communicates with the controller. As used herein, the term haptic refers to devices that convey information to the driver through senses other than hearing and sight. For example, the drivers seat may vibrate when an object is present.
For example, the collision avoidance system may include one or more rear sensors that are located on a rear portion of the vehicle. One or more side and/or front sensors that are positioned along sides and/or front of the vehicle may also be used. Sensors that are employed typically include optical sensors such as lasers, ultrasonic sensors, infrared sensors, radio frequency (RF) sensors and the like. These sensors periodically transmit sensing signals that are directed into a sensing zone. Objects that are located in the sensing zone reflect the sensing signals. The timing and/or amplitude of the reflected signals are processed to estimate a distance between the object and the respective sensor.
The sensor output signal indicates a distance between the sensed object and the sensor. For example, when the driver engages reverse, the output of the rear sensor is monitored. If the rear sensor output indicates that the object is less than a preset distance, the collision avoidance system generates a warning signal (audio, visual and/or haptic). Likewise, if the side sensor signal indicates that an object is less than a preset distance, the collision system also generates a warning signal.
Problems arise as the vehicle moves from one location to another. Preset sensor limits that are suitable for one location and/or speed are often not suitable for other locations and/or speeds. For example, if the preset sensor limits are set for loading and unloading a tractor trailer at a warehouse, the same preset limits may not be suitable for highway driving, city driving or other situations.